What do you call those slide in pop boxes

[pcincome]

I want to add a slide in pop up box to my website, the kind that doesn't get blocked by the pop up blockers. I'm looking for a script I can copy and paste but I guess I don't know the proper name for this that I'm looking for because I can't find anything.

Basically, what I want to do is add a "special promotion" for those who order now that comes up after about 10 seconds on my webpage that everyone will see.

Please advise.
Thank you
Karen